Horner syndrome DDx

Overview

The features of Horner syndrome are:

• Mild ptosis — paresis of Müller muscle (absent on upward gaze due to intact CN3 function)
• Miosis — paralysis of pupillary dilator muscle
• Ipsilateral anhidrosis
• Apparent enophthalmos
• Heterochromia iridis — may be present in congenital Horner syndrome
• Lower eyelid reverse ptosis
• The eye may appear slightly bloodshot due to loss of vasoconstrictor activity in the vessels of the bulbar conjunctiva.

The potential causes are numerous and fall into 3 categories:

• Central lesions (expect anhydrosis of the upper forequarter and coexistent neurological deficits)
• Preganglionic lesions
• Postganglionic lesions (may not affect sweating — main sympathetic outflow to facial vessels and sweat glands is from below the superior cervical ganglion)

Causes

Central lesions (expect anhydrosis of the upper forequarter and coexistent neurological deficits)

Hemisphere lesions

• hemispherectomy
• massive infarction  of one hemisphere
• thalamic hemorrhage
• hypothalamic hemorrhage or infarct

Brainstem lesions

• Vascular events (ischemia or hemorrhage), e.g. Wallenberg syndrome (lateral medullary syndrome)
• Tumor, e.g. pontine glioma
• syringobulbia
• demyelination, e.g. multiple sclerosis
• encephalitis

Neck lesions

• central cord lesions
  • syringomyelia (can cause bilateral Horner syndrome)
  • tumors e.g. ependymoma, glioma
  • central cord syndrome due to trauma
  • arteriovenous malformation

Preganglionic lesions

lesions of cervico-thoracic spinal roots

• cervical ribs
• aortic aneurysms
• avulsion of the lower brachial plexus (e.g. Klumpke’s paralysis)
• severe cervical osteoarthritis with impingement from bony spurs (rare)
• AVM

apical lung disease (some repetition — but a useful category to remember)

• vascular anomalies
• Pancoast’s apical lung tumor
• iatrogenic (chest tube, central catheter)
• infection (eg. apical TB)

cervical sympathetic chain lesions

• local trauma and surgery e.g. thyroidectomy
• tumours
  • Apical lung tumor (Pancoast tumor — usually squamous cell carcnoma)
  • metastases
  • thyroid tumours
  • neurofibroma
  • children — neuroblastoma, lymphoma, metastasis

Postganglionic lesions (may not affect sweating — main sympathetic outflow to facial vessels and sweat glands is from below the superior cervical ganglion)

Neck lesions affecting the superior cervical ganglion

• tumours — e.g. thyroid
• trauma
• surgery (e.g. tonsillectomy)
• degenerative or inflammatory spinal disease

Carotid artery lesions

• spontaneous or traumatic dissection of the carotid artery
• carotid aneurysm
• carotid thrombosis
• pericarotid tumours (Raeder paratrigeminal syndrome (ie, paratrigeminal neuralgia))

Base of skull/ carotid canal

• tumor (nasopharyngeal CA)
• trauma

Headache syndromes

• Cluster headaches
• Migraines

Middle ear (close proximity to the internal carotid artery, alongside which the sympathetic fibers run)

• infection, e.g. otitis media
• tumor e.g. cholesteatoma

Cavernous sinus

• tumour, e.g. pituitary tumours such as prolactinoma
• inflammation — Tolosa-Hunt syndrome
• cavernous carotid fistula or aneurysm
• cavernous sinus thrombosis

References and Links

• Ophthalmology Befuddler 025 — More Befuddling Asymmetry
• Eponymictionary – Johann Friedrich Horner (1831-1886)
• Eponymictionary – Horner Syndrome
• Eponymictionary – Pancoast Tumour

CCC Differential Diagnosis Series
NEURO	Anosmia, Ataxia, Blepharospasm, Bulbar and Pseudobulbar palsy, Central Pontine Myelinosis, Cerebellar Disease, Chorea, Cranial nerve lesions, Dementia, Dystonia, Exophthalmos, Eye trauma, Facial twitches, Fixed dilated pupil, Horner syndrome, Loss of vision, Meningism, Movement disorders, Optic disc abnormality, Parkinsonism, Peripheral neuropathy, Radiculopathy, Red eye, Retinal Haemorrhage, Seizures, Sudden severe headache, Tremor, Tunnel vision
RESP	Bronchial breath sounds, Bronchiectasis, High airway pressures, Massive haemoptysis, Sore throat, Tracheal displacement
CVS	Atrial Fibrillation, Bradycardia, Cardiac Failure, Chest Pain, Murmurs, Post-resuscitation syndrome, Pulseless Electrical Activity (PEA), Pulsus Paradoxus, Shock, Supraventricular tachycardia (SVT), Tachycardia, VT and VF, SVC Obstruction
GIT	Abdominal distension, Abdominal mass, Abdominal pain, Asterixis, Dysphagia, Hepatomegaly, Hepatosplenomegaly, Large bowel obstruction, Liver palpation abnormalities, Lower GI haemorrhage, Malabsorption, Medical causes of abdominal pain, Rectal mass, Small bowel obstruction, Upper GI Haemorrhage
GUT	Genital ulcers, Groin lump, Scrotal mass, Urine colour, Urine Odour, Urine transparency,
MSK	Arthritis, Shoulder pain, Wasting of the small muscles of the hand
DERM	Palmar erythema, Serious skin signs in sick patients, Thickened Tethered Skin, Leg ulcers, Skin Tumour, Acanthosis Nigricans
ENDO	Diabetes Insipidus, Diffuse Goitre, Gynaecomastia, Hirsutism, Hypoglycaemia, SIADH, Weight Loss
HAEM	Splenomegaly
PAEDS	Floppy infant
MISC	Anaphylaxis, Autoimmune associated diseases, Clubbing, Parotid Swelling, Splinter haemorrhages, Toxic agents and abnormal vitals, Toxicological causes of cardiac arrest
IMAGING	CHEST: Atelectasis, Hilar adenopathy, Hilar enlargement on CXR, Honeycomb lung, Increased interstitial markings, Mediastinal widening on mobile CXR, Pulmonary fibrosis, Pseudoinfiltrates on CXR, Pulmonary opacities on CXR, ABDO: Gas on abdominal X-ray, Kidney mass, BRAIN: Intracranial calcification, Intracranial structures with contrast, Ventriculomegaly, OTHER: Pseudofracture on X-Ray,
LABS	LOW: Anaemia, Hypocalcaemia, hypochloraemia, Hypomagnesaemia,  HIGH: Bilirubin and Jaundice, Hyperammonaemia, Hypercalcaemia, Hyperchloraemia, Hyperkalaemia, Hypermagnesaemia,  ACID BASE: Acid base disorders, Resp. acidosis, Resp. alkalosis, Creatinine, CRP, Dipstick Urinalysis, Laboratory Urinalysis, Liver function tests (LFTs), Pleural fluid analysis, Urea, Urea Creatinine Ratio, Uric acid, Urinalysis, Urine Electrolytes

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